A total of up to $2.25 million will be spent this year to trigger a Kootenai River habitat restoration project in Idaho’s panhandle that is intended to improve spawning conditions and survival for endangered white sturgeon.
The Northwest Power and Conservation Council on Tuesday recommended the “within-year” budget request submitted by the Kootenai Tribe of Idaho. The Bonneville Power Administration, which funds the Council’s Columbia River Basin Fish and Wildlife Program, supports the expenditure.
The Kootenai River white sturgeon were listed in 1994 as endangered under the Endangered Species Act. The tribe’s planned habitat actions support the U.S. Fish and Wildlife Service’s draft recovery plan for species and the Libby Dam biological opinion’ reasonable and prudent alternative also specifically acknowledges the management of the river “braided reach” as a priority. The braided reach is upstream of Bonners Ferry, Idaho.
The project is also explicitly linked to and complements the planned expansion of the tribe’s white sturgeon hatchery production program.
The funding is to design, construct, implement, monitor, and evaluate in-stream structures and habitat modifications designed to address factors limiting survival of the endangered Kootenai River white sturgeon.
The 2011 work is part of a three-phase collaborative interagency effort that uses innovative technologies to evaluate enhancement of white sturgeon spawning substrate habitat in the Kootenai River, and implement habitat restoration measures to restore natural recruitment. To date, project activities (Phase 1) have focused on data collection, modeling, critical uncertainties research, planning, design and coordination.
The funding request is for materials acquisition and construction work in the upper portion of the braided reaches between Bonners Ferry, Idaho to the confluence of the Moyie and the Kootenai rivers, according to an April 28 staff memo. Specifically, actions will include bank restoration of approximately 4,000 feet of river bank, addition of large wood to create pool habitat and create roughness features, creation of depositional features, and riparian fencing.
The erosion contributes to sediment loading and degradation of habitat downstream, including primary spawning areas. Reducing bank erosion through the installation of bank structures and vegetation will also provide benefits to the aquatic habitat by increasing or providing overhanging bank cover, shade and channel margin complexity.
Future efforts will again focus on this reach, but also include the straight and meander reaches that extend downstream to the international border.
The Kootenai River white sturgeon is one of 18 land-locked populations of white sturgeon known to occur in western North America. They are restricted to approximately 167.7 river miles extending from Kootenai Falls, Mont., located 31 river miles below Libby Dam in northwest Montana, downstream through the Idaho panhandle and north in Kootenay Lake to Corra Linn Dam at the outflow from Kootenay Lake in British Columbia.
The species has been plagued for decades by poor recruitment – the growth of young fish into the spawning population. The failure was initially thought to be caused by failed natural spawning. However, annual sampling since the early 1990s produced viable naturally produced embryos nearly every year, according to the USFWS.
Since 1990, the Kootenai Hatchery produced numerous successful white sturgeon year classes with good post-release survival rates further confirming gamete viability. Following years of viable embryo collections from the Kootenai River and consistent lack of natural recruitment, the focus of research and recovery efforts shifted to the identification, understanding, and resolution of factors limiting natural recruitment. Such factors include downstream physical habitat changes and reduced population abundance following Libby Dam construction and operation. The dam became operational in 1974.
Researchers say the modification of the sturgeon’s habitat by human activities has contributed to the general lack of recruitment. Those factors include altered hydrograph and thermograph by operations of Libby Dam and the loss of riparian habitat and the natural floodplan due to extensive kids along the Kootenai River for flood control.
The wild population now consists of an aging cohort of large, old fish. The population has declined from approximately 7,000 white sturgeon in the late 1970s to 760 fish in 2000. At the current mortality rate of 9 percent per year, fewer than 500 adults remained in 2005 and there may be fewer than 50 remaining by 2030.
The Kootenai Tribe initiated the sturgeon conservation aquaculture program in 1989 as a stopgap measure designed to ensure preservation of an adequate demographic and genetic base for a healthy future population while adequate habitat restoration actions are implemented and have a chance to take effect.
Hatchery-reared fish planted in the river are expected to take their place but will not reach sexual maturity until about 2020.